Slated to be shut down this summer, the 56-year-old preschool through eighth grade school was given a reprieve in March by Archbishop Salvatore Cordileone after a previous anonymous donor, a parishioner, pledged $200,000 if the school could raise matching funds. The new gift, sent from a bank in San Mateo, more than does that.

"This is frosting on the cake," Arritola said. "The parents are very excited about it. We're all very, very happy."

With the two large donations, plus $65,000 in contributions from parents and parishioners and $70,000 from its endowment fund, the school has been able to meet all the conditions set by the archbishop to remain open. It paid off its $100,000 debt, covered its operating deficit for the current school year and developed a financially viable budget for 2014.

"The school is open for next year," the principal said. "We have a marketing group getting the word out that we are ready to accept new students."

Most of the school's annual budget of $1.3 million comes from tuition, but only 95 of its 133 students pay the full amount. The school has had to provide $158,000 in tuition assistance this year. Coupled with declining enrollment, the financial future did not look good. And, in February, the Rev. Ken Weare, the parish priest who oversees St. Rita's, announced that after more than half a century, the school would have to close this summer.

At a recent meeting, a parent said her 6-year-old son was praying for his school to stay open. As it happens, St. Rita's namesake is an Augustinian nun who's known as the "Saint of the Impossible" because her prayers were often answered.

As if in answer to his prayers and the prayers of other school supporters, St. Rita's administration got a call a week and a half ago from a San Mateo bank, saying a check for the Save St. Rita's Fund from an anonymous donor would be arriving in about a week. It was for $250,000. Sure enough, a bank check from Fiduciary Trust International in San Mateo for that amount arrived right on time.

"We have no idea who it is," Arritola said. "But the check's in the bank. We put it in savings for next year and after. We're trying to get the word out that we are open and are alive and ready to move forward for the next 50 years."